You forgot, Cilan said snivy abandoned it's trainer... There is no trainer with snivy unless your saying about cheren............ Find someone to trade their snivy for something rare like pikachu, If they accept your in luck if they don't... ask them to breed for a snivy. Hope I helped ;) answers take too much approval... breeding is the best way... Also this is how I got snivy in my pokedex in black2 I named it leafysnake.